Electronic Modulation and Mechanistic Study of Ru‐Decorated Porous Cu‐Rich Cuprous Oxide for Robust Alkaline Hydrogen Oxidation and Evolution Reactions

Rational design of high‐efficiency and viable electrocatalysts is essential in overcoming the bottleneck of sluggish alkaline hydrogen oxidation/evolution reaction (HOR/HER) kinetics. In this study, a metal‐organic framework‐derived strategy for constructing a Pt‐free catalyst with Ru clusters anchored on porous Cu−Cu2O@C is proposed. The designed Ru/Cu−Cu2O@C exhibits superior HOR performance, with a mass activity of 2.7 mA μgRu-1 ${{{\rm \mu }{\rm g}}_{{\rm R}{\rm u}}^{-1}}$ at 50 mV, which is about 24 times higher than that of state‐of‐the‐art Pt/C (0.11 mA μgPt-1 ${{{\rm \mu }{\rm g}}_{{\rm P}{\rm t}}^{-1}}$ ). Significantly, Ru/Cu−Cu2O@C also displays impressive HER performance by generating 26 mV at 10 mA cm−2, which exceeds the majority of documented Ru‐based electrocatalysts. Systematic characterization and density functional theory (DFT) calculations reveal that efficient electron transfer between Ru and Cu species results in an attenuated hydrogen binding energy (HBE) of Ru and an enhanced hydroxy binding energy (OHBE) of Cu2O, together with an optimized H2O adsorption energy with Cu2O as the H2O*‐capturing site, which jointly facilitates HOR and HER kinetics. Double duty: A high‐efficiency bifunctional Ru/Cu−Cu2O@C catalyst is fabricated by using a metal‐organic framework‐derived strategy. Electrochemical studies reveal that the designed catalyst exhibits considerable catalytic activity for the hydrogen oxidation and evolution reactions and stability in alkaline electrolyte.